LAUSR

A 55-year-old man presented with four-year history of progressive muscle wasting and weakness. His medical history disclosed advanced stage silicosis. The examination revealed flaccid quadriparesis with proximal amyotrophy. Serum creatine-kinase levels and screening for metabolic and inflammatory disorders were unremarkable. Muscle biopsy showed myopathic findings and the presence of abnormal amorphous and heterogeneous intracytoplasmic and subsarcolemmal content (Figure). Toxic myopathies can result from environmental and occupational exposure to toxic agents1. Silicosis results from the deposition of crystalline silicon dioxide (silica) in lung and is associated with different systemic involvement, including osteoporosis, susceptibility to autoimmune disorders, constrictive pericarditis2 and, rarely, myopathy.